Piano-action spring



July 7, 1936. M. SIEVEKING 2,046,853

PIANO ACTION SPRING Filed July 5, 1935 MAR 7'//VU5 .S/EI EK/NG' INVENTOR ATTORNEY Patented July 7, 1936 UNH'EED stares rarest orriee 6 Claims.

This invention relates to an improved action for grand pianos and more particularly to an improved compound repeating lever and jack spring and means for varying the tension in the spring. 5 This application is a continuation in part of my application Serial No. 733,729, filed July 5, 1934.

In grand piano actions of the type herein shown, it is necessary to periodically regulate the tension exerted by the repeating lever actuating spring. It has been found desirable to make the repeating lever actuating spring as long as possible so as to obtain the maximum resiliency in the spring and so that a heavy gauge spring wire may be employed. The longer the repeating lever actuating spring is made, the more readily will it absorb the rebound of the hammer blow and therefore cause smoother repetition of the action.

An object of this invention is to provide a ClT1- pound piano action spring having free and slidable end portions for actuating the repeating .lever and the jack, a looped end portion and an intermediate portion clamped in the flange, the said spring being made of a single length of wire and the repeating lever actuating portion being of extensive length and pivoted in the support.

Another object of this invention is to provide a. compound piano action spring formed to provide three integrally connected sections, each section having an independent function.

With the above and other objects in View, the invention will be hereinafter more particularly described, and the combination and arrangement of parts will be shown in the accompanying drawing and pointed out in the claims which form part 35 of this specification.

Reference will now be had to the drawing, wherein like numerals of reference designate corresponding parts throughout the several views, in which:

Figure 1 is an elevation of a grand piano action embodying my invention, the parts being partly broken away.

Figure 2 is a View of the spring in inoperative position.

Figure 3 is a view of the spring showing a plurality of coils in the looped end portion thereof.

In the illustrated embodiment of the invention, the numeral l0 indicates a grand piano action comprising a support 5 i and a top flange l2 having a pivot I3 upon which has been mounted a repeating lever I4. A jack I5 has been pivotally mounted on a pivot 25 at one end of the support II.

A compound spring I6 having an upper portion ll, a lower portion l8, a loop l9, a loop extension 20 and an intermediate brace portion 2! has been mounted on a screw or pin 22 in the support H. The upper portion H has a free end 28 in flexed and slidable engagement with the lower surface of the repeating lever I l. The lower portion it is looped at 29 and is thereby mounted in the flange i2 by means of a screw or pin 25 and the lower end of the portion i8 is in flexed engagement and in free and slidable relation with the jack l5. The intermediate portion 2! is mounted in the flange i2 between the pins 22 and 2G and is curved to form an arch. A screw 24 in threaded engagement in the support H has been positioned in right angular relation with the arch portion of the brace 2i and serves for springing the arch and varying the tension in the loop l9 and in the repeating lever actuating portion ii of the spring H6. The loop extension 2? adjoins the brace 2i and is in angular relation therewith. The pressure exerted by the screw 24 against the arch is transmitted by the loop extension 29 to the loop 19 and finally to the upper portion ll of the spring l6 and reacts upwardly against the repeating lever I4. I prefer to shape the brace 2! into an arch to permit extensive movement of the screw and to secure the necessary tension adjustment in the loop I9 without permanent deformation of the brace. To prevent the brace from becoming distorted when pressed upwardly by the screw 24, I have provided the loop extension 29 projecting upwardly from the loop l9 so that when the arch is flexed, the said extension transmits the motion in the arch to the loop without permanent distortion of the brace. I prefer to provide two coils in the looped end portion of the spring to secure greater flexibility of the spring action.

It is to be noted that the compound spring I6 is formed to provide three integrally connected sections, each section having a definite function to perform in the piano action.

It will thus be noted that my compound spring performs all the functions necessary for an efficient grand piano action, in that it makes possible an unusually long repeating lever actuating section, an extensive range of adjustment of the tension in the looped end without any deformation and resulting in a piano action spring having a much longer life than those heretofore in use.

It is to be noticed that the spring is mounted directly on the screws or pins 22 and 26, without the use of felt bushings between the screws or pins and the spring loops.

I claim:

1. In a grand piano action of the character described, comprising a support having a fixed flange and a pivotally mounted jack and a repeating lever, a compound spring having a looped end mounted on a screw or pin in the support and upper and lower portions having free ends, said upper portion having its free end in flexed and slidable engagement with the lower surface of the repeating lever, a lower portion mounted in the flange and having its free end in flexed and slidable engagement with the jack and an intermediate brace portion clamped in the sup port and in the flange, and a screw for springing said brace to vary the tension in said loop and in said repeating lever actuating portion.

2. In a grand piano action of the character described, comprising a support having a fixed flange and a pivotally mounted jack and a repeating lever, a compound spring having a looped end mounted on a screw or pin in the support and upper and lower portions having free ends, said upper portion having its free end in flexed and slidable engagement with the lower surface of the repeating lever, a lower portion mounted in the flange and having its free end in flexed and slidable engagement with the jack and an inter mediate brace portion clamped in the support and in the flange, and a screw for springing said brace to vary the tension in said loop and in said repeating lever actuating portion, said loop comprising two or more coils and a loop extension adjoining said brace.

3. In a grand piano action of the character described, comprising a support having a fixed flange and a pivotally mounted jack and a repeating lever, a spring made of a single length of wire and having a looped end mounted on a screw or pin in the support and upper and lower sections having free ends, said upper section having its free end in flexed and slidable engagement with. the lower surface of the repeating lever, a lower section mounted in the flange and having its free end in flexed and slidable engagement with the jack, an intermediate brace section clamped in the flange and a loop extension integrally connecting said brace and said loop.

4. In a grand piano action of the character described, comprising a support having a fixed flange and a pivotally mounted jack and a repeating lever, a spring made of a single length of wire and having a looped end mounted on a screw or pin in the support and upper and lower sections having free ends, said upper section having its free end in flexed and slidable engagement with the lower surface of the repeating lever, a lower section mounted in the flange and having its free end in flexed and slidable engagement with the jack and an intermediate brace section clamped in the flange.

5. In a grand piano action of the character described, comprising a support having a fixed flange and a pivotally mounted jack and a repeating lever, a spring made of a single length of wire and having a looped end mounted on a screw or pin in the support and upper and lower sections having free ends, said upper section having its free end in flexed and slidable engagement with the lower surface of the repeating lever and a lower section having its free end in flexed and slidable engagement with the jack.

6. In a grand piano action of the character described, comprising a support having a fixed flange and a pivotally mounted jack and a repeating lever, a spring made of a single length or wire and having a looped end mounted on a crew or pin in the support and upper and lower sections having free ends, said upper section having its free end in flexed and slidable engagement with the lower surface of the repeating lever, a lower section having its free end in flexed and slidable engagement with the jack, and means for varying the tension in said loop.

MARTINUS SIEVEKING. 

